| 
           Significant Classes of Amortizable Intangible Assets by Major Category (Detail) (USD $) 
        In Thousands, unless otherwise specified  | 
        
           Sep. 30, 2013 
         | 
        
           Dec. 31, 2012 
         | 
      
|---|---|---|
| Finite-Lived Intangible Assets [Line Items] | ||
| Cost | $ 35,332 | $ 33,874 | 
| Accumulated Amortization | (27,196) | (25,121) | 
| Net | 8,136 | 8,753 | 
| 
           Customer lists and contracts 
         | 
        ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Cost | 17,554 | 17,213 | 
| Accumulated Amortization | (13,834) | (12,665) | 
| Net | 3,720 | 4,548 | 
| 
           Domain and brand names 
         | 
        ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Cost | 11,423 | 11,015 | 
| Accumulated Amortization | (7,864) | (7,192) | 
| Net | 3,559 | 3,823 | 
| 
           Favorable and assigned leases 
         | 
        ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Cost | 2,358 | 1,649 | 
| Accumulated Amortization | (1,676) | (1,594) | 
| Net | 682 | 55 | 
| 
           Other amortizable intangible assets 
         | 
        ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Cost | 3,997 | 3,997 | 
| Accumulated Amortization | (3,822) | (3,670) | 
| Net | $ 175 | $ 327 |